Disintegration device for synthetic material wastes, particularly wastes of endless dimensions

ABSTRACT

A cutting mill for disintegrating synthetic plastic wastes and the like having a rotor provided with cutting blades that operate against a pair of stationary knives. The rotor is disposed within a disintegrating chamber into which material to be disintegrated is fed through a feeding chute. The lower wall of the feeding chute intersects the lower portion of the rotor.

United States Patent [19] Wagner [4 1 Oct. 9, 1973 DISINTEGRATION DEVICE FOR SYNTHETIC MATERIAL WASTES, PARTICULARLY WASTES OF ENDLESS DIMENSIONS Inventor: Matthias Wagner, Klein-Auheim,

Germany Assignee: Moser Stahlbau KG, Klein-Auheim,

Germany Filed: Dec. 21, 1970 Appl. No.: 100,022

Foreign Application Priority Data Dec. 22, 1969 Germany P 19 64 111.3

US. Cl. 241/186 R, 241/189 R Int. Cl. B026 18/44 Field of Search 241/73, 142, 158,

[5 6] References Cited UNITED STATES PATENTS 3,458,143 7/1969 Hofmann 241/186 R 2,813,557 11/1957 Thompson 146/117 R 3,419,223 12/1968 Morin 241/73 2,830,770 4/1958 De Luca 241/73 2,752,099 6/1956 Forman 241/221 Primary Examiner-Robert L. Spruill Attorney-Fulwider, Patton, Rieber, Lee & Utecht [57] ABSTRACT A cutting mill for disintegrating synthetic plastic wastes and the like having a rotor provided with cutting blades that operate against a pair of stationary knives. The rotor is disposed within a disintegrating chamber into which material to be disintegrated is fed through a feeding chute. The lower wall of the feeding chute intersects the lower portion of the rotor.

2 Claims, 3 Drawing Figures DISINTEGRATION DEVICE FOR SYNTHETIC MATERIAL WASTES, PARTICULARLY WASTES OF ENDLESS DIMENSIONS BACKGROUND OF THE INVENTION There have been heretofore proposed cutting mills, used to disintegrate or crush synthetic plastic wastes, particularly those made of endless dimensions, such as pipes, rods and the like, in which a knife fastened onto a rotor operates against two cutting edges, the latter being oppositely situated in one cutting plane. The rotor is disposed in a disintegration chamber. The plane is, in practice, disposed at an angle of about 30 ahead of a vertical line extended through the rotor axis. With this arrangement of material feeding it is necessary to reckon with maximal gravital force or falling force based on the actual cutting point between the lower stationary knife and the rotor knives. It is also necessary to adjust to a tensile or draw-in force of the rotor knife, although such force cannot be exploited because it is practically equal to zero. I

In the following description for the sake of simplicity and in order to get a clearer understanding of the in vention, the tensile or draw-in force of the rotor is referred to as a. Although other essentially vertically acting forces occur at the cutting point, such other forces do serve to locally disintegrate but are disregarded in this description. In the heretofore proposed cutting mills, hardly any pick up of the material by the rotor takes place, and consequently material being cut constant accumulates over the rotor. It is therefor necessary to constantly apply pushing pressure to the material. To overcome the feeding difficulties of prior art devices material to be cut has been fed to the rotor through a feeding chute having an angle of up to about 75 from the horizontal.

In feeding at an angular inclination of up to 75, the

- material to be cut moves jerkwise through the rotor, so

that the worker at the feeding chute is forced to carry out a difficult and health injuring handling of the material even when using gloves. The drawbacks of a sharply inclined feeding chute include an extraordinary costly construction, since the height of the cutting mill must be considerable and may well occupy a second floor level.

SUMMARY OF THE INVENTION It is a major object of the present invention to provide a disintegrating device which can optionally exploit the forces coming into play and likewise to use the minimal height of construction, and this-to be accomplished without any additional draw-in devices for the endless or long material to be disintegrated. Surprisingly, such device utilizes conventional parts of prior art devices.

Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings:

DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of a preferred embodiment of the invention; and

FIGS. 2 and 3 are diagrammatic showings of the operation of the device of FIG. 1.

Referring to FIG. 1 there is shown a disintegrating device embodying the present invention having a feeding chute l for the long waste material to be crushed. Chute 1 has a lower wall 2 defining an introduction plane for the material to be chopped. The upper wall 3 of chute I basically runs parallel with the lower wall 2. A conventional chopping rotor 5 is disposed in a housing part 4 that defines a disintegration chamber 11. Lower wall 2 of feeding chute l' is'centered' on the lower cutting point A in the plane A-B'of two stationary knives 9, 10. Said plane A-B extends clockwise to the rot'ors turning, preferably about 30 aheadof avertical line through the rotor axis. The rotor 5 isequip'ped with the knives 6, 7, 8 which in a known way disintegrate or crush the material received through the chute 1 at the stationary knives 9, 10'.

The inclination of the feeding plane defined by lower wall 2 is shown in FIG. 1 with a 105 angle, based on the cutting plane A-B. Said feeding plane is thus then placed below a horizontal line extending through the rotor axis and, furthermore, brought accurately onto the lower cutting point A of the rotor 5.

At point A, here merely indicated schematically and therefore coinciding with point A on the drawing, the chute I is' arranged in an articulated fashion, whereby the part 4 engages, lapping over or under, in the otherwise rigid housing encasirig the disintegration chamber 11. The housing part 4 may be an upward and lateral extension of upper wall 3 of feeding chute 2.

FIG. 2 shows graphically hitherto used angles in known cutting mills and the invertively proposed angle, this is done under simultaneouspresentation of the prevailing ratio ofth'e' effective gravity force to the occurring tensile force. It should be understood that, basedon the cutting plarieA-B, at 30, only the free drop in reference to the cutting point A becomes active, so that with regard to the disintegration merely the gravity force b appears. At an enlargement of the feedingangle up to a total angle of with reference to the cutting plane A-B, the gravityforce 12' becomes equal to the tensile or drawing-in force a of rotor 5 now becoming active in point A, that is a b. An important effect of the draw-in force a as compared to the gravity force b will, however, not occur in this case, as the falling force, to a certain extent, cancels out the draw-in force.

It'should'be established here, that mean falling force or gravity force for the component b is established as the distance of both horizontal lines through the cutting points A, B since one started out from said component corresponding to the angle of 75, and the state of technology, respectively, however, it was first from this angle on that the second or additional force a of the rotor knife 6', 7, 8 began to be active, as per the present invention.

It should be noted that with regard to the angle of 75, up to which the draw-in force a at least practically hardly has any effect, no one hitherto had exploited the double possibility of using the draw-in force of the rotor on' one hand as a disintegrating force, and on the other hand'a's a draw-in force,-indicated by a in FIGS. 2 and 3.-

It is initially at an angle of for the inclination of the feedingplane 2 with reference to the cutting point A in the cuttingplane A-B that the draw-in force component prevails over the gravital force component so that in this case a is about 2 X b.

It should accordingly be concluded, that the draw-in force at cutting point A cannot act, when a is smaller than b. According to the invention it is necessary that a at all times is greater than b. Thus there is plotted in FIG. 2 the mean or, with regard to types of synthetic material to be chopped, the optimal angle limits of 105, based on the cutting plane A-B, respectively, the cutting point A, for which the equation a E 4 X b applies.

In the event that the angle for the introduction plane, based on A-B, respectively A, amounts to 120, no gravital force will any longer be active, but only the draw-in force, that is to say, an infinite b. It appears, in such a case, that the advantage of the invention already has developed into its full effect, when the worker has brought for the first time the piece of material in question into contact with the rotor at cutting point A. As of this moment the now fully-acting draw-in force a pulls the work piece constantly and to a certain extent automatically into the rotary circle of the rotor, where due to the disintegrating or crushing force of the rotor knives 6, 7 8 the material is crushed so that situations where material was getting stuck in prior cutting mills at the usual inclinations of the feeding plan 2 of the chute I, is completely eliminated by the present invention.

As per FIG. 3, the draw-in force component a corresponding to the angle of 30", respectively, at vertical effect of the goods to be crushed on the cutting line A, is not at aall present, the gravital force b all acts on A.

As per FIG. 3 still no substantial draw-in force occurs in the cutting point A at an inclination of the feeding plane of 75, as, in this case, a b. Compare this to what was stated supra.

As per FIG. 3 at an inclination of the introduction plane 2 of the 90, the draw-in force a is twice as high than the gravital force b, and shows from here on how the actual ratios have confirmed this, that is, their helpful effect as regards the feeding of the individual material to be disintegrated into the described disintegrating device.

As per FIG. 3", at an inclination angle of the feeding plane of 105, the ratio of forces of the drawin force to gravital force is about fourfold. Thus, generally, speaking, an inclination of the feeding plane defined by lower wall 2 which lies in said order of magnitude of about 105, comes out well for most plastic wastes. When this is not possible, the articulated suspension of the feeding chute 1 provided for in point A, gains in importance. One may then according with the requirements, arrange the feeding chute l steeper or flatter.

Even at a completely horizontal arrangement of the feding plane, as per FIG. 3 there is secured a good draw-in of the material to be disintegrated, even though no gravital force whatever is any longer active, but the draw-in force a has attained its maximal value.

In order to bring about the effect of the draw-in force lying in the force of the rotor knife in addition to the effect of the disintegrating force, it is necessary to have the introduction plane defined by lower wall 2 below the horizontal line through the rotor and, furthermore, to center the introduction plane directly on the cutting point A. If one does not do the former, but places the proposed angle within or above the horizontal line through the rotor axis, one cannot attain the desired effect of the invention, because then the forces partially imparted to the material to be crushed by virtue of the rotor knife will effect the work piece in a jerky manner. In addition, in such a case the draw-in force of the rotor knife will thereby disappear, because the abovedescribed feed split at point A is not present, but is at a respectively negative value. The tangential effect on the rotary circle at the point of the knife 6-9 is missing, being only given in point A and perhaps theoretically still farther to the left from this point to the vertical line through the rotor axis. However, said split being moreover present, and first becoming active at point A, between the rotor knives and the stationary knives should, as have been established, be given, in order to secure the feeding as to the material to be crushed.

Said feeding is, according to the practical experiences of the applicant, increased even further by the molecular bonding of the material to be crushed, that is, the characteristic features of the mostly thermoplastic material to be disintegrated, in that the long molecules to a certain extent adhere along their molecule ends and/or additional molecules.

Independently of the draw-in force a, the previously mentioned disintegrating force naturally becomes active at A as function of the number and velocity of the rotor knives, which, however, may be disregarded in the description of the present invention, as such is part of the state of technology.

It is important to notice that according to the present invention, by virtue of the art and arrangement of the feeding chute 2 in a conventional disintegrating device for plastic wastes, besides the known disintegrating force of the rotor knife being present on one hand and the draw-in of long waste material on the other hand, is being brought about. The force provided by the rotor knives not only may be exploited for disintegration, but also for the drawing-in of long plastic wastes.

It is also important to note that the adjustment of the angle of feeding chute 1 permits optimum handling of a variety of the long plastic wastes being brought to disintegration, according to type and dimensions of such wastes. It is possible with a device of the present invention to establish a uniform flow of material to be disintegrated in the device without prior grinding and without requiring additional feeding devices.

A device of the present invention has shown in practice highly desirable economic results, as it became possible by means of such device to disintegrate long waste pieces of plastic not only faster and into more uniform particles, but also to immediately re-use the disintegrated waste material. Furthermore, such device required a comparatively low construction, wherein the height of the device including housing and base amounted to about 1.50 meters at a feeding chute length of about 1.20 meters.

1 claim:

1. A disintegration device for plastic wastes, particularly for wastes of endless dimensions, comprising:

a rotor having a plurality of cutting knives;

a disintegration chamber housing said rotor;

a pair of stationary cutting knives situated opposite one another in said disintegration chamber, the knives of said rotor operating against the stationary knives in the direction of rotation of said rotor at an approximate angle of 30 before a vertical line extended through the axis of rotation of said rotor; and

a feeding chute for wastes to be disintegrated that directs said wastes into said disintegration chamber,

that the feeding chute has relatively narrow and generally parallel upper and lower walls, with the upper wall having an upper and lateral extension forwardly of the rotor to form a part of the disintegration chamber. 

1. A disintegration device for plastic wastes, particularly for wastes of endless dimensions, comprising: a rotor having a plurality of cutting knives; a disintegration chamber housing said rotor; a pair of stationary cutting knives situated opposite one another in said disintegration chamber, the knives of said rotor operating against the stationary knives in the direction of rotation of said rotor at an approximate angle of 30* before a vertical line extended through the axis of rotation of said rotor; and a feeding chute for wastes to be disintegrated that directs said wastes into said disintegration chamber, with the lower wall of said feeding chute intersecting the lower cutting point between the knives of the rotor and the lower stationary knife at an angle of about 90* to 120*, with reference to the cutting plane between the stationary knives.
 2. A device as set forth in claim 1 characterized in that the feeding chute has relatively narrow and generally parallel upper and lower walls, with the upper wall having an upper and lateral extension forwardly of the rotor to form a part of the disintegration chamber. 